Robotic surgical system with motorized movement to a starting pose for a registration or calibration routine

ABSTRACT

A surgical system includes a robotic arm extending from a base, a tracking system configured to track at least one of a first marker attached to a distal end of the robotic arm and a second marker attached to the base, and a controller. The controller is configured to obtain an indication that the base is in position for performing a surgical operation, determine a starting pose for a registration routine for the robotic arm, control the robotic arm to automatically move to the starting pose for the registration or calibration routine, and in response to successful automatic movement to the starting pose for the registration or calibration routine, perform the registration or calibration routine for the robotic arm.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of and priority to U.S. ProvisionalPatent Application No. 63/107,781 filed Oct. 30, 2020, U.S. ProvisionalPatent Application No. 63/125,481 filed Dec. 15, 2020, U.S. ProvisionalPatent Application No. 63/131,654 filed Dec. 29, 2020, and U.S.Provisional Patent Application No. 63/189,508 filed May 17, 2021, theentire disclosures of which are incorporated by reference herein.

BACKGROUND

The present disclosure relates generally to surgical systems fororthopedic surgeries, for example surgical systems that facilitate jointreplacement procedures. Joint replacement procedures (arthroplastyprocedures) are widely used to treat osteoarthritis and other damage toa patient's joint by replacing portions of the joint with prostheticcomponents. Joint replacement procedures can include procedures toreplace hips, knees, shoulders, or other joints with one or moreprosthetic components.

One possible tool for use in an arthroplasty procedure is arobotically-assisted surgical system. A robotically-assisted surgicalsystem typically includes a robotic device that is used to prepare apatient's anatomy to receive an implant, a tracking system configured tomonitor the location of the robotic device relative to the patient'sanatomy, and a computing system configured to monitor and control therobotic device. Robotically-assisted surgical systems, in various forms,autonomously carry out surgical tasks, provide force feedback to a usermanipulating a surgical device to complete surgical tasks, augmentsurgeon dexterity and precision, and/or provide other navigational cuesto facilitate safe and accurate surgical operations.

A surgical plan is typically established prior to performing a surgicalprocedure with a robotically-assisted surgical system. Based on thesurgical plan, the surgical system guides, controls, or limits movementsof the surgical tool during portions of the surgical procedure. Guidanceand/or control of the surgical tool serves to assist the surgeon duringimplementation of the surgical plan. Various features enabling improvedplanning, improved intra-operative assessments of the patientbiomechanics, intraoperative plan adjustments, etc. for use withrobotically-assisted surgical systems or other computer-assistedsurgical systems may be advantageous.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a femur prepared to receive an implantcomponent, according to an exemplary embodiment.

FIG. 2 is an illustration of a surgical system, according to anexemplary embodiment.

FIG. 3 is a flowchart of a first process that can be executed by thesurgical system of FIG. 2, according to an exemplary embodiment.

FIG. 4 is a flowchart of a second process that can be executed by thesurgical system of FIG. 2, according to an exemplary embodiment.

FIG. 5 is a flowchart of a process for providing a motorized movement ofthe robotic arm to a starting pose for a registration or calibrationroutine for the robotic arm, according to an exemplary embodiment.

FIG. 6 is a graphical user interface that may display during executionof the process of FIG. 5, according to an exemplary embodiment.

FIG. 7 is another graphical user interface that may display duringexecution of the process of FIG. 5, according to an exemplaryembodiment.

FIG. 8 is yet another graphical user interface that may display duringexecution of the process of FIG. 5, according to an exemplaryembodiment.

SUMMARY

One implementation of the present disclosure is a surgical system. Thesurgical system includes a robotic arm extending from a base, a trackingsystem configured to track at least one of a first marker attached to adistal end of the robotic arm and a second marker attached to the base,and a controller. The controller is configured to obtain an indicationthat the base is in position for performing a surgical operation,determine a starting pose for a registration routine for the roboticarm, control the robotic arm to automatically move to the starting posefor the registration routine, and in response to successful automaticmovement to the starting pose for the registration routine, perform theregistration or calibration routine for the robotic arm.

Another implementation of the present disclosure is a method ofcontrolling a robotic arm mounted on a base. The method includes guidingthe base to a position relative to a tracking system and determining astarting pose for a registration or calibration routine for the roboticarm. The starting pose corresponds to an expected position of a surgicalfield relative to the base. The method includes controlling the roboticarm to automatically move to the starting pose, and, in response tosuccessful automatic movement to the starting pose for the registrationor calibration routine, providing the registration or calibrationroutine for the robotic arm.

Another implementation of the present disclosure is one or morenon-transitory computer-readable media storing program instructionsthat, when executed by one or more processors, cause the one or moreprocessors to perform operations. The operations include obtaining anindication that a base of a robotic device is positioned relative to atracking system and determining a starting pose for a registration orcalibration routine for a robotic arm extending from the base. Thestarting pose corresponds to an expected position of a surgical fieldrelative to the base. The operations also include controlling therobotic arm to automatically move the robotic arm to the starting poseand, in response to successful automatic movement to the starting posefor the registration or calibration routine, providing the registrationor calibration routine for the robotic arm.

DETAILED DESCRIPTION

Presently preferred embodiments of the invention are illustrated in thedrawings. An effort has been made to use the same or like referencenumbers throughout the drawings to refer to the same or like parts.Although this specification refers primarily to a robotic arm fororthopedic joint replacement, it should be understood that the subjectmatter described herein is applicable to other types of robotic systems,including those used for non-surgical applications, as well as forprocedures directed to other anatomical regions, for example spinal ordental procedures.

Referring now to FIG. 1, a femur 101 as modified during a kneearthroplasty procedure is shown, according to an exemplary embodiment.As shown in FIG. 1, the femur 101 has been modified with multiple planarcuts. In the example shown, the femur 100 has been modified by fivesubstantially planar cuts to create five substantially planar surfaces,namely distal surface 102, posterior chamfer surface 104, posteriorsurface 106, anterior surface 108, and anterior chamfer surface 110. Theplanar surfaces may be achieved using a sagittal saw or other surgicaltool, for example a surgical tool coupled to a robotic device as in theexamples described below. The planar surfaces 102-110 are created suchthat the planar surfaces 102-110 will mate with corresponding surfacesof a femoral implant component. The positions and angular orientationsof the planar surfaces 102-110 may determine the alignment andpositioning of the implant component. Accordingly, operating a surgicaltool to create the planar surfaces 102-110 with a high degree ofaccuracy may improve the outcome of a joint replacement procedure.

As shown in FIG. 1, the femur 101 has also been modified to have a pairof pilot holes 120. The pilot holes 120 extend into the femur 101 andare created such that the pilot holes 120 can receive a screw, aprojection extending from a surface of an implant component, or otherstructure configured to facilitate coupling of an implant component tothe femur 101. The pilot holes 120 may be created using a drill,spherical burr, or other surgical tool as described below. The pilotholes 120 may have a pre-planned position, orientation, and depth, whichfacilitates secure coupling of the implant component to the bone in adesired position and orientation. In some cases, the pilot holes 120 areplanned to intersect with higher-density areas of a bone and/or to avoidother implant components and/or sensitive anatomical features.Accordingly, operating a surgical tool to create the pilot holes 120with a high degree of accuracy may improve the outcome of a jointreplacement procedure.

A tibia may also be modified during a joint replacement procedure. Forexample, a planar surface may be created on the tibia at the knee jointto prepare the tibia to mate with a tibial implant component. In someembodiments, one or more pilot holes or other recess (e.g., fin-shapedrecess) may also be created in the tibia to facilitate secure couplingof an implant component tot eh bone.

In some embodiments, the systems and methods described herein providerobotic assistance for creating the planar surfaces 102-110 and thepilot holes 120 at the femur, and/or a planar surface and/or pilot holes120 or other recess on a tibia. It should be understood that thecreation of five planar cuts and two cylindrical pilot holes as shown inFIG. 1 is an example only, and that the systems and methods describedherein may be adapted to plan and facilitate creation of any number ofplanar or non-planar cuts, any number of pilot holes, any combinationthereof, etc., for preparation of any bone and/or joint in variousembodiments. For example, in a hip or shoulder arthroplasty procedure, aspherical burr may be used in accordance with the systems and methodsherein to ream a curved surface configured to receive a curved implantcup. Furthermore, in other embodiments, the systems and methodsdescribed herein may be used to facilitate placement an implantcomponent relative to a bone (e.g., to facilitate impaction of cupimplant in a hip arthroplasty procedure). Many such surgical andnon-surgical implementations are within the scope of the presentdisclosure.

The positions and orientations of the planar surfaces 102-110, pilotholes 120, and any other surfaces or recesses created on bones of theknee joint can affect how well implant components mate to the bone aswell as the resulting biomechanics for the patient after completion ofthe surgery. Tension on soft tissue can also be affected. Accordingly,systems and methods for planning the cuts which create these surfaces,facilitating intra-operative adjustments to the surgical plan, andproviding robotic-assistance or other guidance for facilitating accuratecreation of the planar surfaces 102-110, other surfaces, pilot holes120, or other recesses can make surgical procedures easier and moreefficient for healthcare providers and improve surgical outcomes.

Referring now to FIG. 2, a surgical system 200 for orthopedic surgery isshown, according to an exemplary embodiment. In general, the surgicalsystem 200 is configured to facilitate the planning and execution of asurgical plan, for example to facilitate a joint-related procedure. Asshown in FIG. 2, the surgical system 200 is set up to treat a leg 202 ofa patient 204 sitting or lying on table 205. In the illustration shownin FIG. 2, the leg 202 includes femur 206 (e.g., femur 101 of FIG. 1)and tibia 208, between which a prosthetic knee implant is to beimplanted in a total knee arthroscopy procedure. In other scenarios, thesurgical system 200 is set up to treat a hip of a patient, i.e., thefemur and the pelvis of the patient. Additionally, in still otherscenarios, the surgical system 200 is set up to treat a shoulder of apatient, i.e., to facilitate replacement and/or augmentation ofcomponents of a shoulder joint (e.g., to facilitate placement of ahumeral component, a glenoid component, and a graft or implant augment).Various other anatomical regions and procedures are also possible.

The robotic device 220 is configured to modify a patient's anatomy(e.g., femur 206 of patient 204) under the control of the computingsystem 224. One embodiment of the robotic device 220 is a haptic device.“Haptic” refers to a sense of touch, and the field of haptics relatesto, among other things, human interactive devices that provide feedbackto an operator. Feedback may include tactile sensations such as, forexample, vibration. Feedback may also include providing force to a user,such as a positive force or a resistance to movement. One use of hapticsis to provide a user of the device with guidance or limits formanipulation of that device. For example, a haptic device may be coupledto a surgical tool, which can be manipulated by a surgeon to perform asurgical procedure. The surgeon's manipulation of the surgical tool canbe guided or limited through the use of haptics to provide feedback tothe surgeon during manipulation of the surgical tool.

Another embodiment of the robotic device 220 is an autonomous orsemi-autonomous robot. “Autonomous” refers to a robotic device's abilityto act independently or semi-independently of human control by gatheringinformation about its situation, determining a course of action, andautomatically carrying out that course of action. For example, in suchan embodiment, the robotic device 220, in communication with thetracking system 222 and the computing system 224, may autonomouslycomplete the series of femoral cuts mentioned above without direct humanintervention.

The robotic device 220 includes a base 230, a robotic arm 232, and asurgical tool 234, and is communicably coupled to the computing system224 and the tracking system 222. The base 230 provides a moveablefoundation for the robotic arm 232, allowing the robotic arm 232 and thesurgical tool 234 to be repositioned as needed relative to the patient204 and the table 205. The base 230 may also contain power systems,computing elements, motors, and other electronic or mechanical systemnecessary for the functions of the robotic arm 232 and the surgical tool234 described below.

The robotic arm 232 is configured to support the surgical tool 234 andprovide a force as instructed by the computing system 224. In someembodiments, the robotic arm 232 allows a user to manipulate thesurgical tool and provides force feedback to the user. In such anembodiment, the robotic arm 232 includes joints 236 and mount 238 thatinclude motors, actuators, or other mechanisms configured to allow auser to freely translate and rotate the robotic arm 232 and surgicaltool 234 through allowable poses while providing force feedback toconstrain or prevent some movements of the robotic arm 232 and surgicaltool 234 as instructed by computing system 224. As described in detailbelow, the robotic arm 232 thereby allows a surgeon to have full controlover the surgical tool 234 within a control object while providing forcefeedback along a boundary of that object (e.g., a vibration, a forcepreventing or resisting penetration of the boundary). In someembodiments, the robotic arm is configured to move the surgical tool toa new pose automatically without direct user manipulation, as instructedby computing system 224, in order to position the robotic arm as neededand/or complete certain surgical tasks, including, for example, cuts ina femur 206.

The surgical tool 234 is configured to cut, burr, grind, drill,partially resect, reshape, and/or otherwise modify a bone. The surgicaltool 234 may be any suitable tool, and may be one of multiple toolsinterchangeably connectable to robotic device 220. For example, as shownin FIG. 2 the surgical tool 234 includes a spherical burr 244. In otherexamples, the surgical tool may also be a sagittal saw, for example witha blade aligned parallel with a tool axis or perpendicular to the toolaxis. The surgical tool may also be a drill, for example with a rotarybit aligned parallel with a tool axis or perpendicular to the tool axis.The surgical tool 234 may also be a holding arm or other supportconfigured to hold an implant component (e.g., cup 28 a, implantaugment, etc.) in position while the implant component is screwed to abone, adhered (e.g., cemented) to a bone or other implant component, orotherwise installed in a preferred position. In some embodiments, thesurgical tool 234 is an impaction tool configured to provide animpaction force to a cup implant to facilitate fixation of the cupimplant to a pelvis in a planned location and orientation.

Tracking system 222 is configured track the patient's anatomy (e.g.,femur 206 and tibia 208) and the robotic device 220 (i.e., surgical tool234 and/or robotic arm 232) to enable control of the surgical tool 234coupled to the robotic arm 232, to determine a position and orientationof modifications or other results made by the surgical tool 234, andallow a user to visualize the bones (e.g., femur 206, the tibia 208,pelvis, humerus, scapula, etc. as applicable in various procedures), thesurgical tool 234, and/or the robotic arm 232 on a display of thecomputing system 224. The tracking system 222 can also be used tocollect biomechanical measurements relating to the patient's anatomy,assess joint gap distances, identify a hip center point, assess nativeor corrected joint deformities, or otherwise collect informationrelating to the relative poses of anatomical features. Moreparticularly, the tracking system 222 determines a position andorientation (i.e., pose) of objects (e.g., surgical tool 234, femur 206)with respect to a coordinate frame of reference and tracks (i.e.,continuously determines) the pose of the objects during a surgicalprocedure. According to various embodiments, the tracking system 222 maybe any type of navigation system, including a non-mechanical trackingsystem (e.g., an optical tracking system), a mechanical tracking system(e.g., tracking based on measuring the relative angles of joints 236 ofthe robotic arm 232), or any combination of non-mechanical andmechanical tracking systems.

In the embodiment shown in FIG. 2, the tracking system 222 includes anoptical tracking system. Accordingly, tracking system 222 includes afirst fiducial tree 240 coupled to the tibia 208, a second fiducial tree241 coupled to the femur 206, a third fiducial tree 242 coupled to thebase 230, one or more fiducials attachable to surgical tool 234, and adetection device 246 configured to detect the three-dimensional positionof fiducials (i.e., markers on fiducial trees 240-242). Fiducial trees240, 241 may be coupled to other bones as suitable for variousprocedures (e.g., pelvis and femur in a hip arthroplasty procedure).Detection device 246 may be an optical detector such as a camera orinfrared sensor. The fiducial trees 240-242 include fiducials, which aremarkers configured to show up clearly to the optical detector and/or beeasily detectable by an image processing system using data from theoptical detector, for example by being highly reflective of infraredradiation (e.g., emitted by an element of tracking system 222). In someembodiments, the markers are active light emitting diodes. Astereoscopic arrangement of cameras 248 on detection device 246 allowsthe position of each fiducial to be determined in 3D-space through atriangulation approach in the example shown. Each fiducial has ageometric relationship to a corresponding object, such that tracking ofthe fiducials allows for the tracking of the object (e.g., tracking thesecond fiducial tree 241 allows the tracking system 222 to track thefemur 206), and the tracking system 222 may be configured to carry out aregistration process to determine or verify this geometric relationship.Unique arrangements of the fiducials in the fiducial trees 240-242(i.e., the fiducials in the first fiducial tree 240 are arranged in adifferent geometry than fiducials in the second fiducial tree 241)allows for distinguishing the fiducial trees, and therefore the objectsbeing tracked, from one another.

Using the tracking system 222 of FIG. 2 or some other approach tosurgical navigation and tracking, the surgical system 200 can determinethe position of the surgical tool 234 relative to a patient's anatomicalfeature, for example femur 206, as the surgical tool 234 is used tomodify the anatomical feature or otherwise facilitate the surgicalprocedure. Additionally, using the tracking system 222 of FIG. 2 or someother approach to surgical navigation and tracking, the surgical system200 can determine the relative poses of the tracked bones.

The computing system 224 is configured to create a surgical plan,control the robotic device 220 in accordance with the surgical plan tomake one or more bone modifications and/or facilitate implantation ofone or more prosthetic components. Accordingly, the computing system 224is communicably coupled to the tracking system 222 and the roboticdevice 220 to facilitate electronic communication between the roboticdevice 220, the tracking system 222, and the computing system 224.Further, the computing system 224 may be connected to a network toreceive information related to a patient's medical history or otherpatient profile information, medical imaging, surgical plans, surgicalprocedures, and to perform various functions related to performance ofsurgical procedures, for example by accessing an electronic healthrecords system. Computing system 224 includes processing circuit 260 andinput/output device 262.

The input/output device 262 is configured to receive user input anddisplay output as needed for the functions and processes describedherein. As shown in FIG. 2, input/output device 262 includes a display264 and a keyboard 266. The display 264 is configured to displaygraphical user interfaces generated by the processing circuit 260 thatinclude, for example, information about surgical plans, medical imaging,settings and other options for surgical system 200, status informationrelating to the tracking system 222 and the robotic device 220, andtracking visualizations based on data supplied by tracking system 222.The keyboard 266 is configured to receive user input to those graphicaluser interfaces to control one or more functions of the surgical system200.

The processing circuit 260 includes a processor and memory device. Theprocessor can be implemented as a general purpose processor, anapplication specific integrated circuit (ASIC), one or more fieldprogrammable gate arrays (FPGAs), a group of processing components, orother suitable electronic processing components. The memory device(e.g., memory, memory unit, storage device, etc.) is one or more devices(e.g., RAM, ROM, Flash memory, hard disk storage, etc.) for storing dataand/or computer code for completing or facilitating the variousprocesses and functions described in the present application. The memorydevice may be or include volatile memory or non-volatile memory. Thememory device may include database components, object code components,script components, or any other type of information structure forsupporting the various activities and information structures describedin the present application. According to an exemplary embodiment, thememory device is communicably connected to the processor via theprocessing circuit 260 and includes computer code for executing (e.g.,by the processing circuit 260 and/or processor) one or more processesdescribed herein.

More particularly, processing circuit 260 is configured to facilitatethe creation of a preoperative surgical plan prior to the surgicalprocedure. According to some embodiments, the preoperative surgical planis developed utilizing a three-dimensional representation of a patient'sanatomy, also referred to herein as a “virtual bone model.” A “virtualbone model” may include virtual representations of cartilage or othertissue in addition to bone. To obtain the virtual bone model, theprocessing circuit 260 receives imaging data of the patient's anatomy onwhich the surgical procedure is to be performed. The imaging data may becreated using any suitable medical imaging technique to image therelevant anatomical feature, including computed tomography (CT),magnetic resonance imaging (MM), and/or ultrasound. The imaging data isthen segmented (i.e., the regions in the imaging corresponding todifferent anatomical features are distinguished) to obtain the virtualbone model. For example, MM-based scan data of a joint can be segmentedto distinguish bone from surrounding ligaments, cartilage,previously-implanted prosthetic components, and other tissue to obtain athree-dimensional model of the imaged bone.

Alternatively, the virtual bone model may be obtained by selecting athree-dimensional model from a database or library of bone models. Inone embodiment, the user may use input/output device 262 to select anappropriate model. In another embodiment, the processing circuit 260 mayexecute stored instructions to select an appropriate model based onimages or other information provided about the patient. The selectedbone model(s) from the database can then be deformed based on specificpatient characteristics, creating a virtual bone model for use insurgical planning and implementation as described herein.

A preoperative surgical plan can then be created based on the virtualbone model. The surgical plan may be automatically generated by theprocessing circuit 260, input by a user via input/output device 262, orsome combination of the two (e.g., the processing circuit 260 limitssome features of user-created plans, generates a plan that a user canmodify, etc.). In some embodiments, the surgical plan may be generatedand/or modified based on distraction force measurements collectedintraoperatively.

The preoperative surgical plan includes the desired cuts, holes,surfaces, burrs, or other modifications to a patient's anatomy to bemade using the surgical system 200. For example, for a total kneearthroscopy procedure, the preoperative plan may include the cutsnecessary to form, on a femur, a distal surface, a posterior chamfersurface, a posterior surface, an anterior surface, and an anteriorchamfer surface in relative orientations and positions suitable to bemated to corresponding surfaces of the prosthetic to be joined to thefemur during the surgical procedure, as well as cuts necessary to form,on the tibia, surface(s) suitable to mate to the prosthetic to be joinedto the tibia during the surgical procedure. As another example, thepreoperative plan may include the modifications necessary to createholes (e.g., pilot holes 120) in a bone. As another example, in a hiparthroplasty procedure, the surgical plan may include the burr necessaryto form one or more surfaces on the acetabular region of the pelvis toreceive a cup and, in suitable cases, an implant augment. Accordingly,the processing circuit 260 may receive, access, and/or store a model ofthe prosthetic to facilitate the generation of surgical plans. In someembodiments, the processing circuit facilitate intraoperativemodifications tot eh preoperative plant.

The processing circuit 260 is further configured to generate a controlobject for the robotic device 220 in accordance with the surgical plan.The control object may take various forms according to the various typesof possible robotic devices (e.g., haptic, autonomous). For example, insome embodiments, the control object defines instructions for therobotic device to control the robotic device to move within the controlobject (i.e., to autonomously make one or more cuts of the surgical planguided by feedback from the tracking system 222). In some embodiments,the control object includes a visualization of the surgical plan and therobotic device on the display 264 to facilitate surgical navigation andhelp guide a surgeon to follow the surgical plan (e.g., without activecontrol or force feedback of the robotic device). In embodiments wherethe robotic device 220 is a haptic device, the control object may be ahaptic object as described in the following paragraphs.

In an embodiment where the robotic device 220 is a haptic device, theprocessing circuit 260 is further configured to generate one or morehaptic objects based on the preoperative surgical plan to assist thesurgeon during implementation of the surgical plan by enablingconstraint of the surgical tool 234 during the surgical procedure. Ahaptic object may be formed in one, two, or three dimensions. Forexample, a haptic object can be a line, a plane, or a three-dimensionalvolume. A haptic object may be curved with curved surfaces and/or haveflat surfaces, and can be any shape, for example a funnel shape. Hapticobjects can be created to represent a variety of desired outcomes formovement of the surgical tool 234 during the surgical procedure. One ormore of the boundaries of a three-dimensional haptic object mayrepresent one or more modifications, such as cuts, to be created on thesurface of a bone. A planar haptic object may represent a modification,such as a cut, to be created on the surface of a bone. A curved hapticobject may represent a resulting surface of a bone as modified toreceive a cup implant and/or implant augment. A line haptic object maycorrespond to a pilot hole to be made in a bone to prepare the bone toreceive a screw or other projection.

In an embodiment where the robotic device 220 is a haptic device, theprocessing circuit 260 is further configured to generate a virtual toolrepresentation of the surgical tool 234. The virtual tool includes oneor more haptic interaction points (HIPs), which represent and areassociated with locations on the physical surgical tool 234. In anembodiment in which the surgical tool 234 is a spherical burr (e.g., asshown in FIG. 2), a HIP may represent the center of the spherical burr.Where one HIP is used to virtually represent a surgical tool, the HIPmay be referred to herein as a tool center point (TCP). If the surgicaltool 234 is an irregular shape, for example as for a sagittal saw, thevirtual representation of the sagittal saw may include numerous HIPs.Using multiple HIPs to generate haptic forces (e.g. positive forcefeedback or resistance to movement) on a surgical tool is described inU.S. application Ser. No. 13/339,369, titled “System and Method forProviding Substantially Stable Haptics,” filed Dec. 28, 2011, and herebyincorporated by reference herein in its entirety. In one embodiment ofthe present invention, a virtual tool representing a sagittal sawincludes eleven HIPs. As used herein, references to an “HIP” are deemedto also include references to “one or more HIPs.” As described below,relationships between HIPs and haptic objects enable the surgical system200 to constrain the surgical tool 234.

Prior to performance of the surgical procedure, the patient's anatomy(e.g., femur 206) is registered to the virtual bone model of thepatient's anatomy by any known registration technique. One possibleregistration technique is point-based registration, as described in U.S.Pat. No. 8,010,180, titled “Haptic Guidance System and Method,” grantedAug. 30, 2011, and hereby incorporated by reference herein in itsentirety. Alternatively, registration may be accomplished by 2D/3Dregistration utilizing a hand-held radiographic imaging device, asdescribed in U.S. application Ser. No. 13/562,163, titled “RadiographicImaging Device,” filed Jul. 30, 2012, and hereby incorporated byreference herein in its entirety. Registration also includesregistration of the surgical tool 234 to a virtual tool representationof the surgical tool 234, so that the surgical system 200 can determineand monitor the pose of the surgical tool 234 relative to the patient(i.e., to femur 206). Registration of allows for accurate navigation,control, and/or force feedback during the surgical procedure.

The processing circuit 260 is configured to monitor the virtualpositions of the virtual tool representation, the virtual bone model,and the control object (e.g., virtual haptic objects) corresponding tothe real-world positions of the patient's bone (e.g., femur 206), thesurgical tool 234, and one or more lines, planes, or three-dimensionalspaces defined by forces created by robotic device 220. For example, ifthe patient's anatomy moves during the surgical procedure as tracked bythe tracking system 222, the processing circuit 260 correspondinglymoves the virtual bone model. The virtual bone model thereforecorresponds to, or is associated with, the patient's actual (i.e.physical) anatomy and the position and orientation of that anatomy inreal/physical space. Similarly, any haptic objects, control objects, orother planned automated robotic device motions created during surgicalplanning that are linked to cuts, modifications, etc. to be made to thatanatomy also move in correspondence with the patient's anatomy. In someembodiments, the surgical system 200 includes a clamp or brace tosubstantially immobilize the femur 206 to minimize the need to track andprocess motion of the femur 206.

For embodiments where the robotic device 220 is a haptic device, thesurgical system 200 is configured to constrain the surgical tool 234based on relationships between HIPs and haptic objects. That is, whenthe processing circuit 260 uses data supplied by tracking system 222 todetect that a user is manipulating the surgical tool 234 to bring a HIPin virtual contact with a haptic object, the processing circuit 260generates a control signal to the robotic arm 232 to provide hapticfeedback (e.g., a force, a vibration) to the user to communicate aconstraint on the movement of the surgical tool 234. In general, theterm “constrain,” as used herein, is used to describe a tendency torestrict movement. However, the form of constraint imposed on surgicaltool 234 depends on the form of the relevant haptic object. A hapticobject may be formed in any desirable shape or configuration. As notedabove, three exemplary embodiments include a line, plane, orthree-dimensional volume. In one embodiment, the surgical tool 234 isconstrained because a HIP of surgical tool 234 is restricted to movementalong a linear haptic object. In another embodiment, the haptic objectis a three-dimensional volume and the surgical tool 234 may beconstrained by substantially preventing movement of the HIP outside ofthe volume enclosed by the walls of the three-dimensional haptic object.In another embodiment, the surgical tool 234 is constrained because aplanar haptic object substantially prevents movement of the HIP outsideof the plane and outside of the boundaries of the planar haptic object.For example, the processing circuit 260 can establish a planar hapticobject corresponding to a planned planar distal cut needed to create adistal surface on the femur 206 in order to confine the surgical tool234 substantially to the plane needed to carry out the planned distalcut.

For embodiments where the robotic device 220 is an autonomous device,the surgical system 200 is configured to autonomously move and operatethe surgical tool 234 in accordance with the control object. Forexample, the control object may define areas relative to the femur 206for which a cut should be made. In such a case, one or more motors,actuators, and/or other mechanisms of the robotic arm 232 and thesurgical tool 234 are controllable to cause the surgical tool 234 tomove and operate as necessary within the control object to make aplanned cut, for example using tracking data from the tracking system222 to allow for closed-loop control.

Referring now to FIG. 3, a flowchart of a process 300 that can beexecuted by the surgical system 200 of FIG. 2 is shown, according to anexemplary embodiment. Process 300 may be adapted to facilitate varioussurgical procedures, including total and partial joint replacementsurgeries.

At step 302, a surgical plan is obtained. The surgical plan (e.g., acomputer-readable data file) may define a desired outcome of bonemodifications, for example defined based on a desired position ofprosthetic components relative to the patient's anatomy. For example, inthe case of a knee arthroplasty procedure, the surgical plan may provideplanned positions and orientations of the planar surfaces 102-110 andthe pilot holes 120 as shown in FIG. 1. The surgical plan may begenerated based on medical imaging, 3D modeling, surgeon input, etc.

At step 304, one or more control boundaries, such as haptic objects, aredefined based on the surgical plan. The one or more haptic objects maybe one-dimensional (e.g., a line haptic), two dimensional (i.e.,planar), or three dimensional (e.g., cylindrical, funnel-shaped, curved,etc.). The haptic objects may represent planned bone modifications(e.g., a haptic object for each of the planar surfaces 102-110 and eachof the pilot holes 120 shown in FIG. 1), implant components, surgicalapproach trajectories, etc. defined by the surgical plan. The hapticobjects can be oriented and positioned in three-dimensional spacerelative to a tracked position of a patient's anatomy.

At step 306, a pose of a surgical tool is tracked relative to the hapticobject(s), for example by the tracking system 222 described above. Insome embodiments, one point on the surgical tool is tracked. In otherembodiments, (e.g., in the example of FIGS. 4-5) two points on thesurgical tool are tracked, for example a tool center point (TCP) at atip/effective end of the surgical tool and a second interaction point(SIP) positioned along a body or handle portion of the surgical tool. Inother embodiments, three or more points on the surgical tool aretracked. A pose of the surgical tool is ascertained relative to acoordinate system in which the one or more haptic objects are definedand, in some embodiments, in which the pose of one or more anatomicalfeatures of the patient is also tracked.

At step 308, the surgical tool is guided to the haptic object(s). Forexample, the display 264 of the surgical system 200 may display agraphical user interface instructing a user on how (e.g., whichdirection) to move the surgical tool and/or robotic device to bring thesurgical tool to a haptic object. As another example, the surgical toolmay be guided to a haptic object using a collapsing haptic boundary asdescribed in U.S. Pat. No. 9,289,264, the entire disclosure of which isincorporated by reference herein. As another example, the robotic devicemay be controlled to automatically move the surgical tool to a hapticobject.

In an embodiment where the robotic device is controlled to automaticallymove the surgical tool to the haptic object (referred to as motorizedalignment or automated alignment), the robotic device may be controlledso that a duration of the alignment is bounded by preset upper and lowertime thresholds. That is, across various instances of process 300 andmultiple procedures, automated alignment in step 308 may be configuredto always take between a first amount of time (the lower time threshold)and a second amount of time (the upper time threshold). The lower timethreshold may be selected such that the robotic device moves over a longenough duration to be perceived as well-controlled and to minimizecollision or other risks associated with high speed. The upper timethreshold may be selected such that the robotic device moves over ashort enough duration to avoid user impatience and provide improvedusability. For example, the upper time threshold hold may beapproximately five seconds in an example where the lower time thresholdsis approximately three seconds. In other embodiments, a single durationsetpoint is used (e.g., four seconds). Step 308 can include optimizing apath for the robotic device such that the step 308 ensures successfulalignment to the haptic object while also satisfying the upper and lowertime thresholds or duration setpoint.

At step 310, the robotic device is controlled to constrain movement ofthe surgical tool based on the tracked pose of the surgical tool and theposes of one or more haptic objects. The constraining of the surgicaltool may be achieved as described above with reference to FIG. 2.

At step 312, exit of the surgical tool from the haptic object(s) isfacilitated, i.e., to release the constraints of a haptic object. Forexample, in some embodiments, the robotic device is controlled to allowthe surgical tool to exit a haptic object along an axis of the hapticobject. In some embodiments, the surgical tool may be allowed to exitthe haptic object in a pre-determined direction relative to the hapticobject. The surgical tool may thereby be removed from the surgical fieldand the haptic object to facilitate subsequent steps of the surgicalprocedure. Additionally, it should be understood that, in some cases,the process 300 may return to step 308 where the surgical tool is guidedto the same or different haptic object after exiting a haptic object atstep 312.

Process 300 may thereby be executed by the surgical system 200 tofacilitate a surgical procedure. Features of process 300 are shown inFIGS. 4-8 below according to some embodiments, and such features can becombined in various combinations in various embodiments and/or based onsettings selected for a particular procedure. Furthermore, it should beunderstood that the features of FIGS. 4-8 may be provided while omittingsome or all other steps of process 300. All such possibilities arewithin the scope of the present disclosure.

Referring now to FIG. 4, a flowchart of a process 400 for facilitatingsurgical planning and guidance is shown, according to an exemplaryembodiment. The process 400 may be executed by the surgical system 200of FIG. 2, in some embodiments. In some cases, the process 300 isexecuted as part of executing the process 400.

At step 402, segmented pre-operative images and other patient data areobtained, for example by the surgical system 200. For example, segmentedpre-operative CT images or MRI images may be received at the computingsystem 224 from an external server. In some cases, pre-operative imagesof a patient's anatomy are collected using an imaging device andsegmented by a separate computing system and/or with manual user inputto facilitate segmentation. In other embodiments, unsegmentedpre-operative images are received at the computing system 224 and thecomputing system 224 is configured to automatically segment the images.The segmented pre-operative images can show the geometry, shape, size,density, and/or other characteristics of bones of a joint which is to beoperated on in a procedure performed using process 400.

Other patient data can also be obtained at step 402. For example, thecomputing system 224 may receive patient information from an electronicmedical records system. As another example, the computing system 224 mayaccept user input of patient information. The other patient data mayinclude a patient's name, identification number, biographicalinformation (e.g., age, weight, etc.), other health conditions, etc. Insome embodiments, the patient data obtained at step 402 includesinformation specific to the procedure to be performed and the relevantpre-operative diagnosis. For example, the patient data may indicatewhich joint the procedure will be performed on (e.g., right knee, leftknee). The patient data may indicate a diagnosed deformity, for exampleindicating whether a knee joint was diagnosed as having a varusdeformity or a valgus deformity. This or other data that may facilitatethe surgical procedure may be obtained at step 402.

At step 404, a system setup, calibration, and registration workflow isprovided, for example by the surgical system 200. The system setup,calibration, and registration workflows may be configured to prepare thesurgical system 200 for use in facilitating a surgical procedure. Forexample, at step 404, the computer system 224 may operate to providegraphical user interfaces that include instructions for performingsystem setup, calibration, and registrations steps. The computer system224 may also cause the tracking system 222 to collect tracking data andcontrol the robotic device 220 to facilitate system setup, calibration,and/or registration. The computer system 224 may also receiving trackingdata from the tracking system 222 and information from the computersystem 224 and use the received information and data to calibrate therobotic device 220 and define various geometric relationships betweentracked points (e.g., fiducials, markers), other components of thesurgical system 200 (e.g., robotic arm 232, surgical tool 234, probe),and virtual representations of anatomical features (e.g., virtual bonemodels).

The system setup workflow provided at step 404 may include guiding therobotic device 220 to a position relative to a surgical table and thepatient which will be suitable for completing an entire surgicalprocedure without repositioning the robotic device 220. For example, thecomputer system 224 may generate and provide a graphical user interfaceconfigured to provide instructions for moving a portable cart of therobotic device 220 into a preferred position. In some embodiments, therobotic device 220 can be tracked to determine whether the roboticdevice 220 is properly positioned. Once the cart is positioned, in someembodiments the robotic device 220 is controlled to automaticallyposition the robotic arm 232 in a pose suitable for initiation ofcalibration and/or registration workflows.

The calibration and registration workflows provided at step 404 mayinclude generating instructions for a user to perform variouscalibration and registration tasks while operating the tracking system222 to generate tracking data. The tracking data can then be used tocalibrate the tracking system 222 and the robotic device 220 and toregister the first fiducial tree 240, second fiducial tree 241, andthird fiducial tree 242 relative to the patient's anatomical features,for example by defining geometric relationships between the fiducialtrees 240-242 and relevant bones of the patient in the example of FIG.2. The registration workflow may include tracking a probe used to touchvarious points on the bones of a joint. In some embodiments, providingthe registration workflow may include providing instructions to couple acheckpoint (e.g., a screw or pin configured to be contacted by a probe)to a bone and tracking a probe as the probe contacts the checkpoint andas the probe is used to paint (i.e., move along, touch many pointsalong) one or more surfaces of the bone. The probe can be moved andtracked in order to collect points in or proximate the joint to beoperated upon as well as at other points on the bone (e.g., at ankle orhip for a knee surgery).

In some embodiments, providing the registration workflow includesgenerating instructions to move the patient's leg to facilitatecollection of relevant tracking data that can be used to identify thelocation of a biomechanical feature, for example a hip center point.Providing the registration workflow can include providing audio orvisual feedback indicating whether the leg was moved in the propermanner to collect sufficient tracking data. Various methods andapproaches for registration and calibration can be used in variousembodiments. Step 404 may include steps performed before or after aninitial surgical incision is made in the patient's skin to initiate thesurgical procedure.

At step 406, an initial assessment workflow is provided, for example bythe surgical system 200. The initial assessment workflow provides aninitial assessment of the joint to be operated upon based on trackedposes of the bones of the joint. For example, the initial assessmentworkflow may include tracking relative positions of a tibia and a femurusing data from the tracking system while providing real-timevisualizations of the tibia and femur via a graphical user interface.The computing system 224 may provide instructions via the graphical userinterface to move the tibia and femur to different relative positions(e.g., different degrees of flexion) and to exert different forces onthe joint (e.g., a varus or valgus force). In some embodiments, theinitial assessment workflow includes determine, by the surgical system200 and based on data from the tracking system 222, whether thepatient's joint has a varus or valgus deformity, and, in someembodiments, determining a magnitude of the deformity. In someembodiments, the initial assessment workflow may include collecting datarelating to native ligament tension or native gaps between bones of thejoint. In some embodiments, the initial assessment workflow may includedisplaying instructions to exert a force on the patient's leg to placethe joint in a corrected state corresponding to a desired outcome for ajoint arthroplasty procedure, and recording the relative poses of thebones and other relevant measurements while the joint is in thecorrected state. The initial assessment workflow thereby results incollection of data that may be useful for the surgical system 200 or asurgeon in later steps of process 400.

At step 408, an implant planning workflow is provided, for example bythe surgical system 200. The implant planning workflow is configured tofacilitate users in planning implant placement relative to the patient'sbones and/or planning bone cuts or other modifications for preparingbones to receive implant components. Step 408 may include generating,for example by the computing system 324, three-dimensional computermodels of the bones of the joint (e.g., a tibia model and a femur model)based on the segmented medical images received at step 402. Step 408 mayalso include obtaining three-dimensional computer models of prostheticcomponents to be implanted at the joint (e.g., a tibial implant modeland a femoral implant model). A graphical user interface can begenerated showing multiple views of the three-dimensional bone modelswith the three-dimensional implant models shown in planned positionsrelative to the three-dimensional bone models. Providing the implantplanning workflow can include enabling the user to adjust the positionand orientation of the implant models relative to the bone models.Planned cuts for preparing the bones to allow the implants to beimplanted at the planned positions can then be automatically based onthe positioning of the implant models relative to the bone models.

The graphical user interface can include data and measurements frompre-operative patient data (e.g., from step 402) and from the initialassessment workflow (step 406) and/or related measurements that wouldresult from the planned implant placement. The planned measurements(e.g., planned gaps, planned varus/valgus angles, etc.) can becalculated based in part on data collected via the tracking system 222in other phases of process 400, for example from initial assessment instep 406 or trialing or tensioning workflows described below withreference to step 412.

The implant planning workflow may also include providing warnings(alerts, notifications) to users when an implant plan violates variouscriteria. In some cases, the criteria can be predefined, for examplerelated to regulatory or system requirements that are constant for allsurgeons and/or for all patients. In other embodiments, the criteria maybe related to surgeon preferences, such that the criteria for triggeringa warning can be different for different surgeons. In some cases, thecomputing system 224 can prevent the process 400 from moving out of theimplant planning workflow when one or more of certain criteria are notmet.

The implant planning workflow provided at step 408 thereby results inplanned cuts for preparing a joint to receive prosthetic implantcomponents. In some embodiments, the planned cuts include a planartibial cut and multiple planar femoral cuts, for example as describedabove with reference to FIG. 1. The planned cuts can be defined relativeto the virtual bone models used in the implant planning workflow at step408. Based on registration processes from step 404 which define arelationship between tracked fiducial markers and the virtual bonemodels, the positions and orientations of the planned cuts can also bedefined relative to the tracked fiducial markers, (e.g., in a coordinatesystem used by the tracking system 222). The surgical system 200 isthereby configured to associate the planned cuts output from step 408with corresponding planes or other geometries in real space.

At step 410, a bone preparation workflow is provided, for example by thesurgical system 200. The bone preparation workflow includes guidingexecution of one or more cuts or other bone modifications based on thesurgical plan created at step 408. For example, as explained in detailabove with reference to FIGS. 2-3, the bone preparation workflow mayinclude providing haptic feedback which constrains the surgical tool 234to a plane associated with a planned cut to facilitate use of thesurgical tool 234 to make that planned cut. In other embodiments, thebone preparation workflow can include automatically controlling therobotic device 220 to autonomously make one or more cuts or other bonemodifications to carry out the surgical plan created at step 408. Inother embodiments, the bone preparation workflow comprises causing therobotic device 220 to hold a cutting guide, drill guide, jig, etc. in asubstantially fixed position that allows a separate surgical tool to beused to execute the planned cut while being confined by the cuttingguide, drill guide, jig, etc. The bone preparation workflow can thusinclude control of a robotic device in accordance with the surgicalplan.

The bone preparation workflow at step 410 can also include displayinggraphical user interface elements configured to guide a surgeon incompleting one or more planned cuts. For example, the bone preparationworkflow can include tracking the position of a surgical tool relativeto a plane or other geometry associated with a planned cut and relativeto the bone to be cut. In this example, the bone preparation workflowcan include displaying, in real-time, the relative positions of thesurgical tool, cut plane or other geometry, and bone model. In someembodiments, visual, audio, or haptic warnings can be provided toindicate completion or start of an event or step of the procedure, entryor exit from a state or virtual object, interruptions to performance ofthe planned cut, deviation from the planned cut, or violation of othercriteria relating to the bone preparation workflow.

In some embodiments, step 410 is provided until all bone cuts planned atstep 408 are complete and the bones are ready to be coupled to theimplant components. In other embodiments, for example as shown in FIG.4, a first iteration of step 410 can include performing only a portionof the planned cuts. For example, in a total knee arthroplastyprocedure, a first iteration of step 410 can include making a tibial cutto provide a planar surface on the tibia without modifying the femur inthe first iteration of step 410.

Following an iteration of the bone preparation workflow at step 410, theprocess 400 can proceed to step 412. At step 412 a mid-resectiontensioning workflow or a trialing workflow is provided, for example bythe surgical system 200. The mid-resection tensioning workflow isprovided when less than all of the bone resection has been completed.The trialing workflow is provided when all resections have been madeand/or bones are otherwise prepared to be temporarily coupled to trialimplants. The mid-resection tensioning workflow and the trialingworkflow at step 412 provide for collection of intraoperative datarelating to relative positions of bones of the joint using the trackingsystem 222 including performing gap measurements or other tensioningprocedures that can facilitate soft tissue balancing and/or adjustmentsto the surgical plan.

For example, step 412 may include displaying instructions to a user tomove the joint through a range of motion, for example from flexion toextension, while the tracking system 222 tracks the bones. In someembodiments, gap distances between bones are determined from datacollected by the tracking system 222 as a surgeon places the joint inboth flexion and extension. In some embodiments, soft tissue tension ordistraction forces are measured. Because one or more bone resectionshave been made before step 412 and soft tissue has been affected by theprocedure, the mechanics of the joint may be different than during theinitial assessment workflow of step 402 and relative to when thepre-operative imaging was performed. Accordingly, providing forintra-operative measurements in step 412 can provide information to asurgeon and to the surgical system 200 that was not availablepre-operatively and which can be used to help fine tune the surgicalplan.

From step 412, the process 400 returns to step 408 to provide theimplant planning workflow again, now augmented with data collectedduring a mid-resection or trialing workflow at step 412. For example,planned gaps between implants can be calculated based on theintraoperative measurements collected at step 414, the planned positionof a tibial implant relative to a tibia, and the planned position of afemoral implant relative to a femur. The planned gap values can then bedisplayed in an implant planning interface during step 408 to allow asurgeon to adjust the planned implant positions based on the calculatedgap values. In various embodiments, a second iteration of step 408 toprovide the implant planning workflow incorporates various data fromstep 412 in order to facilitate a surgeon in modifying and fine-tuningthe surgical plan intraoperatively.

Steps 408, 410, and 412 can be performed multiple times to provide forintra-operative updates to the surgical plan based on intraoperativemeasurements collected between bone resections. For example, in somecases, a first iteration of steps 408, 410, and 412 includes planning atibial cut in step 408, executing the planned tibial cut in step 410,and providing a mid-resection tensioning workflow in step 414. In thisexample, a second iteration of steps 408, 410, and 412 can includeplanning femoral cuts using data collected in the mid-resectiontensioning workflow in step 408, executing the femoral cuts in step 410,and providing a trialing workflow in step 412. Providing the trialingworkflow can include displaying instructions relating to placing trialimplants on the prepared bone surfaces, and, in some embodiments,verifying that the trial implants are positioned in planned positionsusing the tracking system 222. Tracking data can be collected in atrialing workflow in step 412 relating to whether the trial implants areplaced in acceptable positions or whether further adjustments to thesurgical plan are needed by cycling back to step 408 and making furtherbone modifications in another iteration of step 410.

In some embodiments, executing process 400 can include providing userswith options to jump between steps of the process 400 to enter a desiredworkflow. For example, a user can be allowed to switch between implantplanning and bone preparation on demand. In other embodiments, executingprocess 400 can include ensuring that a particular sequence of steps ofprocess 400 are followed. In various embodiments, any number ofiterations of the various steps can be performed until a surgeon issatisfied that the bones have been properly prepared to receive implantcomponents in clinically-appropriate positions.

As shown in FIG. 4, the process 400 includes step 414 where implantationof prosthetic components is facilitated. Once the bones have beenprepared via step 410, the prosthetic components can be implanted. Insome embodiments, step 414 is executed by the surgical system 200 byremoving the robotic arm 232 from the surgical field and otherwisegetting out of the way to allow a surgeon to fix the prostheticcomponents onto the bones without further assistance from the surgicalsystem 200. In some embodiments, step 414 includes displayinginstructions and/or navigational information that supports a surgeon inplacing prosthetic components in the planned positions. In yet otherembodiments, step 414 includes controlling the robotic arm 232 to placeone or more prosthetic components in planned positions (e.g., holding aprosthetic component in the planned position while cement cures, whilescrews are inserted, constraining an impaction device to plannedtrajectory). Process 400 can thereby result in prosthetic componentsbeing affixed to modified bones according to an intra-operativelyupdated surgical plan.

Referring generally to FIGS. 5-8, features are shown which can beprovided during the system setup, calibration, and registration workflowat step 404 of process 400 of FIG. 4. In particular, the features ofFIGS. 5-8 relating to a portion of step 404 in which registration of therobotic arm is performed in order to allow for tracking of the roboticarm using data from the tracking system. As described in detail below,the features of FIGS. 5-8 relate to motorized movement of the roboticarm to a starting pose for a registration or calibration routine(procedure, process, workflow) for the robotic arm.

Motorized movement of the robotic arm as described below may addressvarious challenges relating to system setup, calibration, andregistration under step 404. In the example of FIG. 2, the components ofthe surgical system 200 are all repositionable between surgicaloperations. For example, the detection device 246 of the tracking system222 may be mounted on a wheeled cart that can be moved between surgicaloperations. The base 230 of the robotic device 220 may also be moveable,for example provided with wheels, a steering system, and a brakingsystem. Such mobility can facilitate use of an operating for surgeriesthat do not utilize the surgical system 200 in addition to operationsthat utilize the surgical system 200. However, such mobility can alsocreate a challenge in properly arranging the components of the surgicalsystem 200 for optimal functionality when the surgical system 200 is tobe used in a procedure.

One aspect of this challenge is in finding a proper starting pose of therobotic arm for performing a registration or calibration routine for therobotic arm. For various reasons, for example relating to trackingaccuracy, it may be desirable to perform a registration or calibrationroutine with a distal end of the robotic arm 232 as close as possible towhere it will be during use of the robotic arm 232 during the surgicalprocedure. However, that location may not be readily apparent to a user,especially new users, as it should be identified at an early stage of anoperation before other surgical tasks have been initiated. Additionally,a starting pose for a registration or calibration routine preferablycorresponds to starting joint angles of the robotic arm 232 which willprovide sufficient range of motion and degrees of freedom for therobotic arm 232 in order to complete both the registration orcalibration routine and the steps of the surgical procedure. Suchconstraints may not be clear ahead of time to the user of a surgicalsystem 200. Furthermore, the registration or calibration routine mayrequire a clear line-of-sight between a trackable array coupled to adistal end of the robotic device and the detectors 246 of the trackingsystem throughout the registration or calibration routine, providinganother constraint on selecting a proper placement of the starting poseof the robotic arm for a surgical procedure which may not be readilyapparent to a user. Also, because computer-assisted navigationtechniques available in later phases of a surgical operation rely uponcompletion of registration, such techniques are not available to assistin putting the robotic arm in a proper pose for starting a registrationor calibration routine. Accordingly, a threshold challenge of providingthe robotic device in a proper starting pose should be solved in orderto provide a reliable, highly-accurate, user-friendly registration orcalibration routine.

Referring now to FIG. 5, a process 500 for providing a motorizedmovement of the robotic arm to a starting pose for a registration orcalibration routine for the robotic arm is shown, according to anexemplary embodiment. The process 500 can be executed using the surgicalsystem 200 described above, and reference thereto is made in thedescription of the process 500. The process 500 can also be used withother robotic systems in various embodiments.

At step 502, the detector 246 of the tracking system 222 is positioned,for example in an operating room. That is, the detector 246 is set(parked, locked, braked, fixed, etc.) in the position where it willpreferably stay for a duration of the surgical procedure. In someembodiments, the surgical system 200 is configured to provide, via adisplay screen 264, instructions for positioning the detector 246 of thetracking system 222.

At step 504, the robotic device 220 and the tracking system 222 arepositioned and parked relative to one another, for example such that therobotic device 220 and the detector 246 of the tracking system 222 areseparated by less than or equal to a preset distance. For example, themobile base 230 can be rolled, steered, etc. into a desired positionrelative to the tracking system 222 and relative to other structures inthe operating room (e.g., relative to a table/bed on which a patient canbe positioned during a surgical procedure). As another example, themobile base 230 could be parked first and the tracking system 222 (e.g.,the detector 246 of the tracking system 222) can be moved toward themobile base 230. In some cases, the mobile base 230 is positioned suchthat the patient will be located between the mobile base 230 and thedetector 246 of the tracking system 222. In some embodiments, thesurgical system 200 is configured to provide, via a display screen 264,instructions for positioning the detector 246 of the tracking system222. In some cases, the tracking system 222 is used to provide liveupdates of the position of the base 230 relative to a target parkingposition displayed on the display screen 264. Accordingly, the base 230can be guided to a parking position relative to other components used inthe operating room.

At step 506, a trackable array (fiducial tree, end effector array) iscoupled to a distal end of the robotic arm 232. For example, a surgicaltool 234 may be attached to the distal end of the robotic arm 232 andthe trackable array can be attached to the surgical tool 234 so as to becoupled to the distal end of the robotic arm 232. As mentioned abovewith reference to the example of FIG. 1, a fiducial tree (tracker basearray) 242 can be coupled to the base 230. In such examples, followingstep 506, an end effector array is positioned at a distal end of therobotic arm 232 and the base array 242 is positioned at the base 230(e.g., proximate a proximal end of the robotic arm 232). The base array242 is omitted in some embodiments, and may be replaced by a trackablearray on the robotic arm 232 in some embodiments. In other embodiments,the trackable array is incorporated into the surgical tool 234. In yetother embodiments, machine vision is used to obtain positions of one ormore of the surgical tool 234, the base 230, a point on the robotic arm232, etc. without use of trackable arrays.

At step 508, a starting pose of the robotic arm for a registration orcalibration routine is determined. The starting pose may be associatedwith an expected position of a surgical field in which a surgicalprocedure will be performed using a surgical tool 234 attached to therobotic arm 232. For example, the starting pose may be representative ofcutting poses that will be used during the surgical procedure. In someembodiments, the processing circuit 260 determines the starting posebased on relative positions of the detector 246 and the base 230 of therobotic device 220. For example, the starting pose may be determined toensure or improve the likelihood that the end effector tracker remainswithin the line-of-sight of the detector 246 of the tracking system 222throughout the calibration and registration procedures. In someembodiments, the starting pose is automatically calculated based on oneor more of these criteria each time the process 500 is performed (e.g.,for each surgical operation). In other embodiments, the starting pose ispredetermined or preprogrammed based on the various criteria, forexample such that properly parking the base 230 in an acceptableposition ensures that the starting pose will be properly situated in theoperating room.

In some embodiments of step 508, the starting pose for registration orcalibration is determined by performing an optimization process to finda best working volume for cuts in a total knee arthroplasty procedure(or other procedure in other applications). The optimization process mayconsider factors such as estimated calibration error for the roboticarm, anthropomorphic models of the surgeon/user relating to usabilityand ergonomics, surgeon height, surgeon preferences, probable positionof the patient on the table, and other operating room constraints. Thedetermination may be made using an assumption that the camera ispositioned across the knee from the robotic device 220. The startingpose may be selected as the center of the optimized working volume. Insome embodiments of step 508, the starting pose is selected tocorresponding to a working volume where the robotic arm 232 has a lowestcalibration error and estimated error due to compliance in the armduring use. Additionally, the starting pose may be selected such thatmotorized alignment ends in a plane that is parallel to the expectedorientation of the cameras 248 of the tracking system 222.

At step 510, an approach area is defined around the starting pose. Theapproach area defines a space in which motorized movement of the roboticarm to the starting pose can be initiated as described below withreference to steps 512-518. In some embodiments, the approach area isdefined by a virtual boundary, for example a sphere centered on thestarting pose. In some embodiments, the approach area is defined in acoordinate system of the tracking system 222. In some embodiments, theapproach area is defined in terms of joint angles of the robotic arm232.

The approach area may be defined in various ways in various embodiments.For example, in some embodiments the approach area is defined to balancemultiple considerations. Reducing a size of the approach area can reducea risk of the robotic arm 232 colliding with objects or people in theoperating room motorized movement. Also, determination of the approacharea can include ensuring that the approach area is sufficiently largeto enable a user to easily move the end effector in the approach area.The approach area can also be defined to ensure that it is consistentwith the range of the robotic arm so that the robotic arm is capable ofreaching the approach area. The approach area can also be sized andpositioned based on a preferred distance and speed for the motorizedmotion in later steps, i.e., such that the robotic arm enters theapproach area at a location which is within an acceptable distance ofthe starting pose for the registration or calibration procedure and fromwhich the motorized motion can be performed in an acceptable amount oftime (e.g., less than a threshold duration) and at an acceptablevelocity (e.g., less than a threshold velocity). The approach area mayvary based on whether the procedure is to be performed on a right orleft side of the patient's body (e.g., right knee vs. left knee).

At step 511, instructions are displayed which instruct a user to movethe robotic arm into the approach area. For example, the processingcircuit 260 can cause the display screen 264 to display a graphical userinterface including a graphic that illustrates movement of the roboticarm into the approach area. The graphical user interface may alsoinclude text-based instructions. An example graphical user interfacethat can be displayed at step 511 is shown in FIG. 6 and described indetail with reference thereto below.

At step 512, entry of the robotic arm 232 into the approach area isdetected. The robotic arm 232 can be moved into the approach areamanually by a user. That is, the user can exert a force on the roboticarm 232 to push the robotic arm into the approach area. In someembodiments, detecting entry of the robotic arm 232 into the approacharea includes tracking the end effector array (trackable markers)attached to the distal end of the robotic arm 232 with the trackingsystem 222 and determining whether the distal end of the robotic arm 232is in an approach area defined in a coordinate system used by thetracking system 222. In other embodiments, detecting entry of therobotic arm 232 includes checking joint angles of the robotic arm 232(e.g., from encoders at the joints) against one or more criteria whichdefine the approach area in terms of joint angles of the robotic arm232. In such embodiments, detecting entry of the robotic arm 232 intothe approach area can be performed independently of the tracking system222. Thus, step 512 corresponds to determining that the robotic arm 232is in a position from which it can be automatically moved to thestarting pose determined in step 508.

At step 514, instructions are displayed which instruct a user toactivate (e.g., engage, disengage, depress, release, etc.) an inputdevice or otherwise input a command to initiate motorized movement ofthe robotic arm to the starting pose for the registration or calibrationroutine. For example, the processing circuit 260 may cause the displayscreen 264 to display a graphical user interface that includes a graphicshowing a user engaging an input device, for example depressing atrigger positioned proximate the surgical tool 234, depressing a footpedal, or otherwise engaging some other input device (e.g., mouse,button, pedal, trigger, switch, sensor). As another example, amicrophone may be communicable with the processing circuit 260 such thata voice command can be used to initiate motorized movement. As anotherexample, touchless gesture control could be used, for example using amachine vision approach, to provide a command to initiate automatedalignment. As another example, the command can be input by moving theend effector in a particular direction. The command can be provided by aprimary user (e.g., surgeon) in the sterile field and/or by a secondperson, for example a technician or nurse elsewhere in the operatingroom. An example user interface for display at step 514 is shown in FIG.7 and described in detail below with reference thereto.

Accordingly, in step 514, an option is provided for the user to initiatemotorized movement of the robotic arm to the starting pose for theregistration or calibration routine. In alternative embodiments, steps514 and 516 are omitted and motorized movement is automaticallyinitiated when the robotic arm 232 enters the approach area withoutadditional input from a user.

At step 516, a determination is made of whether the user is stillactivating the input device as instructed in step 514. For example,engagement of the input device (e.g., depression of a trigger) maycreate an electrical signal from the input device to the processingcircuit 260. In such an example, the processing circuit 260 candetermine whether the user is activating the input device based onwhether the electrical signal is received. For example, presence of thesignal from the input device may cause the processing circuit 260 todetermine at step 516 that the user is engaging the input device,whereas absence of the signal from the input device may cause theprocessing circuit 260 to determine at step 516 that the user is notengage the input device.

If a determination is made at step 516 that the user is not activatingthe input device (i.e., “No” at step 516 in FIG. 5)(i.e., deactivationof the input device, for example by engagement or disengagement of aninput device), the process 500 returns to step 514 to continue todisplay instructions to the user to engage the input device to initiatemotorized movement to the starting pose. In some embodiments, anaudible, haptic, or other alert may provide if the user does not engagethe input device after a certain amount of time or according to someother criteria that indicates that the user is not aware of theinstructions to engage the input device to initiate motorized movementto the starting pose.

If a determination is made at step 516 that the user is engaging theinput device (i.e., “Yes” at step 516 in FIG. 5), the process 500 movesto step 518 where motors of the robotic arm 232 are controlled to drivethe robotic arm to the starting pose for the registration or calibrationroutine. That is, in step 518 the robotic device 220 is controlled toprovide motorized movement of the robotic arm 232 from a pose where theuser first engages the input device to the starting pose for aregistration or calibration routine identified in step 508. In someembodiments, motorized movement is performed along a shortest/straightpath to the starting pose. In some embodiments, step 518 includesautomatically planning a path between an initial position and thestarting poses for the registration or calibration routine, and thencontrol the robotic arm to provide movement along the planned path. Thepath can be straight or curved. In some embodiments, the path is plannedsuch that motorized movement of the robotic arm 232 in step 518 willtake between a lower duration threshold and an upper duration threshold(e.g., between approximately 4 seconds and approximately six seconds).

Motorized movement of the robotic arm 232 to the starting pose in step518 can includes movement in one to six degrees of freedom, for exampleincluding moving a distal end of the robotic arm 232 to a locationidentified by the starting pose and providing rotations to align with anorientation identified by the starting pose. In some embodiments,motorized movement includes arranging joint angles of the robotic arm232 in a preferred (e.g., predefined) arrangement, for example anarrangement that facilitate calibration, registration, and/or completionof the surgical procedure. In other embodiments, for example for a sevendegree of freedom robot, motorized movement can be performed such thatthe target starting position of the end effector (surgical tool 234) isdefined and used for control without regards to angles or otherpositions of the arm 232.

As illustrated in FIG. 5, the processing circuit 260 can continue tomake the determination in step 516 of whether the user is engaging theinput device. In some scenarios, the user will engage the input deviceto initiate motorized movement, but then disengage from the input devicebefore the motorized movement has resulted in arrival at the startingpose for the registration or calibration routine. In such scenarios, andin some embodiments, the processing circuit 260 determines in step 516that the user is no longer engaging the input device and stops themotorized movement of the robotic arm. Process 500 can then return tostep 514, where a user is instructed to restart motorized movement byreengaging the input device.

If the user continues to engage the input device, motorized movementcontinues until the robotic arm 232 reaches the starting pose for theregistration or calibration routine. At step 520, in response toreaching the starting pose, a registration or calibration routine isinitiated. Initiating the registration or calibration routine caninclude starting one or more data collection processes, for exampletracking of an end effector array and base array by the tracking system222, any other tracking of the robotic device 220, controlling therobotic arm 232 to provide additional motorized movements or toconstrain manual movement of the robotic arm 232, and/or providinginstructions for user actions to support the registration or calibrationroutine via the display screen 264.

For example, FIG. 8 (described in detail below) shows a graphical userinterface that can be displayed via the display screen 264 in responseto the robotic arm 232 reaching the starting pose for the registrationor calibration routine. As described in detail below, the registrationor calibration routine in the example of FIG. 8 includes providinginstructions to a user to cause the user to manually move the distal tipof the surgical tool 234 coupled to the robotic arm 232 to the verticesof a cube while the end effector array is in view of the detector 246 ofthe tracking system. The cube in such an example is located proximatethe starting pose for the registration or calibration routine identifiedin step 508, for example centered on the starting point or having afirst vertex at the starting pose. The motorized movement to thestarting pose can be seen as guiding the surgical tool 234 and/ortracking array to this cube. Geometries other than a cube can be used inother embodiments, for example selected such that each joint of the armis exercised during the registration or calibration routine.

By ensuring that the registration or calibration routine (procedure) isperformed from the system-determined starting pose, process 500 canreduce or eliminate potential human-caused variations in initiation ofthe registration or calibration routine, which may increase thereliability and accuracy of the registration or calibration routine.Additionally, by providing motorized movement to the starting pose,efficiency and usability of the system can be improved. The process 500thereby provides improvements over alternative approaches to initiatinga registration or calibration routine.

Referring now to FIG. 6, a graphical user interface 600 is shown,according to an exemplary embodiment. The graphical user interface 600can be displayed on the display screen 264 under control of theprocessing circuit 260. The graphical user interface 600 displaysinstructions for moving the robotic arm 232 into an approach area forinitiation of motorized movement, and can correspond to step 511 ofprocess 500. The graphical user interface shows a graphic 602illustrating a user 604 manually pushing a distal end of the robotic arm232 into an approach area 606, including an illustration of a preferredgrip or handling technique for manipulating the robotic arm 232 to movethe robotic arm 232 into approach area 606. The graphic 602 includes adepiction of the patient 608 to facilitate a user in determining whichdirection to move the robotic arm (e.g., toward the patient asillustrated in FIG. 6). In some embodiments, the graphic 602 is updatedin real-time (i.e., at a high enough frequency to appear as real-time toa typical user) to depict actual, real-time movement of the robotic arm232. The graphic 602 is designed to be intuitive for a user to interpretand follow in order to move the robotic arm 232 into the approach areain accordance with step 511 of process 500.

The graphical user interface 600 also includes text-based messages 610that can include instructions, alerts, warning, updates, etc. withrespect to operation of the surgical system 200. In the example shown,the text-based messages 610 include instructions to bring the roboticarm 232 in Approach Mode as shown, i.e., to move the robotic arm 232into the approach area as illustrated in the graphic 602. The text-basedmessages 610 also indicate that the surgical tool is successfullyconnected to the robotic arm, and that the end effector array is notcurrently visible to the detector 246 of the tracking system. Motorizedmovement via process 500 can move the end effector from outside thefield of view of the detector 246 as indicated by the text-basedmessages 610 and into the field of view of the detector 246 to enable aregistration or calibration routine. Information can also becommunicated to the user via sounds emitted by a speaker of the surgicalsystem 200 (e.g., acoustic feedback), forces provided via the roboticdevice 220 (e.g., haptic feedback), or indicators lights positioned onthe robotic arm 232 or elsewhere in the surgical system 200. Thesevarious types of feedback can be provided at various events in operationof the surgical system 200, for example when the approach area isentered, when motorized movement can be initiated, when motorizedmovement is initiated, successful motorized movement, and/or successfulor unsuccessful completion of various other events and steps describedherein.

A user can follow the graphical and text-based instructions of graphicaluser interface 600 (and/or acoustic or haptic feedback) to move therobotic arm 232 into the approach area 606. In response, the processingcircuit 260 detects entry of the robotic arm 232 into the approach areaat step 512, and updates the display screen 264 to display instructionsto engage an input device to initiate motorized movement to the startingpose for the registration or calibration routine at step 514 as in FIG.7, for example.

Referring now to FIG. 7, a graphical user interface 700 that can bedisplayed on the display screen 264 at step 514 is shown, according toan exemplary embodiment. The graphical user interface 700 is configuredto instruct a user to engage an input device or otherwise input acommand to initiate motorized movement of the robotic arm to thestarting pose. The graphical user interface 700 is also configured toinstruct a user to check whether an end effector array is properlymounted on the surgical tool 234. For example, the graphical userinterface 700 may display a quality metric based on the orientation ofthe end effector and a result of checking whether the end effector arrayis fully seated. The graphical user interface 700 may display a warningor instructions to correct the mounting on the end effector array insome scenarios, for example if an improper orientation of the endeffector array is detected.

The graphical user interface 700 includes a graphic 702 of the surgicaltool 234 attached to the distal end of the robotic arm 232, as is thecase when step 514 of process 500 is initiated. The graphic 702 shows anend effector array 704 attached to the surgical tool, and includes acall-out window 706 showing a zoomed-in view of an interface between theend effector array 704 and the surgical tool 234. The graphic 702 showsthe end effector array 704 as properly attached to the surgical tool234, such that the graphic 702 may thereby encourage a user to verifythat this connection is properly made at the physical surgical tool. Thegraphic 702 also shows that the surgical tool 234 includes a trigger708. In other embodiments, another input device is shown instead of thetrigger 708 (e.g., foot pedal, mouse, button, switch, sensor).

The graphical user interface 700 also includes an icon 710 configured tocommunicate an instruction to press the trigger 708. The icon 710includes a depiction of the surgical tool 234, including the trigger 708and a hand holding a grip portion of the surgical tool 234 with a fingerof the hand positioned on the trigger 708. An arrow is included in theicon 710 indicating that the finger is depressing the trigger 708. Theicon 710 is thereby configured to show depression of the trigger 708 bya user. In embodiments where other types of commands are received toinitiate the motorized movement, the icon 710 can be adaptedaccordingly. For example, the icon 710 can show depression or release ofa foot pedal, selection of a button, engagement of some other sensor,verbal statement of a command (e.g., “Okay Robot, Start Movement”), usergesture or body movement, etc. as appropriate in various embodiments toindicate to the user that the system is ready to accept the user inputto initiate the motorized movement.

The graphical user interface 700 also includes text-based messages 712that can include instructions, alerts, updates, statuses, warnings, etc.regarding operation of the surgical system 200. As shown in FIG. 7, thetext-based messages 712 includes instructs to hold the trigger 708 tostart alignment, i.e., to initiated motorized movement to the startingpose for the registration or calibration routine. The text-basedmessages 712 also indicate that the also indicate that the surgical toolis successfully connected to the robotic arm, and that the end effectorarray is not currently visible to the detector 246 of the trackingsystem, or provide other information relating to occlusion of one ormore tracking arrays. Motorized movement via process 500 can move theend effector from outside the field of view of the detector 246 asindicated by the text-based messages 610 and into the field of view ofthe detector 246 to enable a registration or calibration routine. Incontrast to other alignment, navigation, or control functionality inother portions of a procedure where control is performed based on datafrom the tracking system 222, the motorized movement here can beinitiated without visibility of the end effector or the end effectorarray to the detector 246, without visibility of the base array to thedetector 246, and before calibration and registration have beenperformed.

When the trigger 708 (or other input device in various embodiments) isengaged or activated, for example by depression of the trigger 708 asinstructed in the graphical user interface 700 as shown in FIG. 7, therobotic device 220 can be controlled to cause motorized movement of therobotic arm 232 to the starting pose for the registration or calibrationroutine (i.e., steps 516-518 of process 500). The graphical userinterface 700 can continue to be displayed during motorized alignment,for example updated with an icon or text-based message 712 indicatingthat motorized movement is occurring and that the trigger 708 (or otherinput device in various embodiments) can be deactivated or disengaged(e.g., released, un-depressed) to pause the motorized movement. Theinput device may work as a dead-man switch so that the motorizedmovement is stopped if the input device is released, but may also workas a selectable brake in some embodiments, i.e., such that an inputdevice can be engaged to pause the motorized movement. In response toreaching the starting pose (i.e., step 520), the processing circuit 260can cause the display screen to display the graphical user interface 800shown in FIG. 8.

Referring now to FIG. 8, a graphical user interface 800 guiding a userthrough a registration or calibration routine for the robotic arm 232 isshown, according to an exemplary embodiment. In the embodiment shown,the graphical user interface 800 includes a graphic 802 instructing theuser to manually move the surgical tool 234 through a series ofpositions. In particular, the graphic 802 guides a user in moving atracked tip 806 of the surgical tool 234 to vertices of a virtual cube804. The virtual cube 804 corresponds to a volume in real spaceproximate the starting pose for the registration or calibration routine,with vertices positioned several inches from one another, for example.Other geometries can be used in various embodiments, for exampleselected to ensure that all joints are exercised during the registrationor calibration routine. The virtual cube 804 includes vertices that canchange colors to indicate the next vertex the tip 806 of the surgicaltool 234 should be moved to, which vertices have already been contactedby the tip 806 of the surgical tool 234, and which vertices have not yetbeen contacted by the tip 806 of the surgical tool 234. The graphicaluser interface 800 can be updated in real-time such that movement of thereal, physical surgical tool 234 causes corresponding movement of thevirtual representation of the surgical tool 234 in the graphical userinterface 800. The graphic 802 thereby provides real-time navigationalguidance to facilitate the user in performing manual movements of thesurgical tool 234 to complete a registration or calibration routine. Inother embodiments, automated movements are used.

The graphical user interface 800 is also shown as including selectablebuttons 808 that allow a user to select to restart the registration orcalibration routine, free the robotic arm from the registration orcalibration routine, or collect a point (i.e., record a position of endeffector tracker as part of the registration or calibration routine).The graphical user interface 800 thereby provides interactivity with andcontrol over the registration or calibration routine. The graphical userinterface 800 also shows text-based instructions 810 explaining how therobotic arm is to be moved through the virtual cube 804 as guided in thegraphic 802 while keeping the end effector array visible to the detector246 of the tracking system 222. A sound can be emitted from the surgicalsystem 200 at each successful capture (e.g., when the end effector meetsa vertex of the virtual cube 804). A haptic feedback, for example avibration, or an indicator light can also be used to indicate asuccessful capture during the registration or calibration process.

The text-based instructions 810 may include real-time coordinates of thetracked tip of the surgical tool 234 which may be useful to a user. Thegraphical user interface 800 is also shown as including an icon 812which can change colors to indicate whether the end effector array iscurrently visible to the detector 246 (e.g., red for not visible, greenfor visible). Other icons may be similarly included to showconnectivity, proper operation, etc. of other components of the surgicalsystem 200. The graphical user interface 800 is also shown to include aregistration results progress bar 814 which can update to show progressthrough the registration process and/or indicate a quality of theregistration process.

The graphical user interface 800 thereby includes various features whichmay be helpful in guiding a user through a registration or calibrationroutine for the surgical system 200 starting at and following step 520of process 500. In some embodiments, for example the example shown inFIGS. 7-8, successful completion of the registration or calibrationroutine allows the end effector array 704 to be removed from thesurgical tool 234 while enabling the tracking system 222 to accuratelydetermine positions of the surgical tool 234 by tracking the base array242 and using data indicating rotations of joints of the robotic arm232. In such examples, various steps of processes 300 and 400 can thenbe performed without a trackable marker attached directly to thesurgical tool 234. It should be noted that the automated, motorizedmovement of process 500 occurs before registration or calibration iscompleted to enable the tracking and control approaches used for therobotic arm 232 in later steps of process 400, for example during bonepreparation.

The term “coupled” and variations thereof, as used herein, means thejoining of two members directly or indirectly to one another. Suchjoining may be stationary (e.g., permanent or fixed) or moveable (e.g.,removable or releasable). Such joining may be achieved with the twomembers coupled directly to each other, with the two members coupled toeach other using a separate intervening member and any additionalintermediate members coupled with one another, or with the two memberscoupled to each other using an intervening member that is integrallyformed as a single unitary body with one of the two members. If“coupled” or variations thereof are modified by an additional term(e.g., directly coupled), the generic definition of “coupled” providedabove is modified by the plain language meaning of the additional term(e.g., “directly coupled” means the joining of two members without anyseparate intervening member), resulting in a narrower definition thanthe generic definition of “coupled” provided above. Such coupling may bemechanical, electrical, magnetic, or fluidic.

References herein to the positions of elements (e.g., “top,” “bottom,”“above,” “below”) are merely used to describe the orientation of variouselements in the FIGURES. It should be noted that the orientation ofvarious elements may differ according to other exemplary embodiments,and that such variations are intended to be encompassed by the presentdisclosure.

The hardware and data processing components used to implement thevarious processes, operations, illustrative logics, logical blocks,modules and circuits described in connection with the embodimentsdisclosed herein may be implemented or performed with a general purposesingle- or multi-chip processor, a digital signal processor (DSP), anapplication specific integrated circuit (ASIC), a field programmablegate array (FPGA), or other programmable logic device, discrete gate ortransistor logic, discrete hardware components, or any combinationthereof designed to perform the functions described herein. A generalpurpose processor may be a microprocessor, or, any conventionalprocessor, controller, microcontroller, or state machine. A processoralso may be implemented as a combination of computing devices, such as acombination of a DSP and a microprocessor, a plurality ofmicroprocessors, one or more microprocessors in conjunction with a DSPcore, or any other such configuration. In some embodiments, particularprocesses and methods may be performed by circuitry that is specific toa given function. The memory (e.g., memory, memory unit, storage device)may include one or more devices (e.g., RAM, ROM, Flash memory, hard diskstorage) for storing data and/or computer code for completing orfacilitating the various processes, layers and modules described in thepresent disclosure. The memory may be or include volatile memory ornon-volatile memory, and may include database components, object codecomponents, script components, or any other type of informationstructure for supporting the various activities and informationstructures described in the present disclosure. According to anexemplary embodiment, the memory is communicably connected to theprocessor via a processing circuit and includes computer code forexecuting (e.g., by the processing circuit or the processor) the one ormore processes described herein.

The present disclosure contemplates methods, systems and programproducts on any machine-readable media for accomplishing variousoperations. The embodiments of the present disclosure may be implementedusing existing computer processors, or by a special purpose computerprocessor for an appropriate system, incorporated for this or anotherpurpose, or by a hardwired system. Embodiments within the scope of thepresent disclosure include program products comprising machine-readablemedia for carrying or having machine-executable instructions or datastructures stored thereon. Such machine-readable media can be anyavailable media that can be accessed by a general purpose or specialpurpose computer or other machine with a processor. By way of example,such machine-readable media can comprise RAM, ROM, EPROM, EEPROM, orother optical disk storage, magnetic disk storage or other magneticstorage devices, or any other medium which can be used to carry or storedesired program code in the form of machine-executable instructions ordata structures and which can be accessed by a general purpose orspecial purpose computer or other machine with a processor. Combinationsof the above are also included within the scope of machine-readablemedia. Machine-executable instructions include, for example,instructions and data which cause a general purpose computer, specialpurpose computer, or special purpose processing machines to perform acertain function or group of functions.

Although the figures and description may illustrate a specific order ofmethod steps, the order of such steps may differ from what is depictedand described, unless specified differently above. Also, two or moresteps may be performed concurrently or with partial concurrence, unlessspecified differently above. Such variation may depend, for example, onthe software and hardware systems chosen and on designer choice. Allsuch variations are within the scope of the disclosure. Likewise,software implementations of the described methods could be accomplishedwith standard programming techniques with rule-based logic and otherlogic to accomplish the various connection steps, processing steps,comparison steps, and decision steps.

What is claimed is:
 1. A surgical system comprising: a robotic armextending from a base; a tracking system configured to track at leastone of a first marker attached to a distal end of the robotic arm and asecond marker attached to the base; a controller configured to:determine a starting pose for a registration or calibration routine forthe robotic arm; control the robotic arm to automatically move to thestarting pose for the registration or calibration routine; and inresponse to successful automatic movement to the starting pose for theregistration or calibration routine, perform the registration orcalibration routine for the robotic arm.
 2. The surgical system of claim1, wherein the controller is further configured to: define an approacharea; in response to the robotic arm entering the approach area, providean option to initiate the automatic movement to the starting pose forthe registration or calibration routine.
 3. The surgical system of claim1, further comprising a display screen and an input device, wherein thecontroller is configured: cause the display screen to display a firstgraphic instructing a user to move the robotic arm into the approacharea; in response to the robotic arm entering the approach area, causethe display screen to display a second graphic instructing the user toengage the input device to select the option to initiate the automaticmovement.
 4. The surgical system of claim 1, wherein the controller isconfigured to control the robotic arm to automatically move to thestarting pose for the registration or calibration routine by: providingthe automatic movement if an input device of the robotic device isactivated; and stopping the automatic movement if the input device isnot activated.
 5. The surgical system of claim 4, wherein the inputdevice is a trigger positioned at a distal end of the robotic arm. 6.The surgical system of claim 1, comprising the first marker attached tothe distal end of the robotic arm and the second marker attached to thebase; wherein the registration or calibration routine providesregistration of the distal end of the robotic arm relative to the markerattached to the base based on data from the tracking system indicatingtracked positions of the marker attached to the distal end of therobotic device.
 7. The surgical system of claim 1, wherein thecontroller is configured to determine the starting pose based on anexpected position of a surgical field relative to the base.
 8. A methodof controlling a robotic arm mounted on a movable base, comprising:determining a starting pose for a registration or calibration routinefor the robotic arm, the starting pose corresponding to an expectedposition of a surgical field relative to the movable base; controllingthe robotic arm to automatically move to the starting pose; and inresponse to successful automatic movement to the starting pose for theregistration or calibration routine, providing the registration orcalibration routine for the robotic arm.
 9. The method of claim 8,further comprising: defining an approach area; in response to therobotic arm entering the approach area, providing an option for a userto initiate the automatic movement to the starting pose for theregistration or calibration routine.
 10. The method of claim 9, furthercomprising: displaying, via display screen, a first graphic instructinga user to move the robotic arm into the approach area; and in responseto the robotic arm entering the approach area, displaying, via thedisplay screen to display a second graphic instructing the user toengage an input device to initiate the automatic movement.
 11. Themethod of claim 8, wherein controlling the robotic arm to automaticallymove to the starting pose for the registration or calibration routinecomprises: providing the automatic movement if an input device of therobotic device is activated; and stopping the automatic movement if theinput device is not activated.
 12. The method of claim 8, whereinproviding the registration or calibration routine comprises tracking,with the tracking system, a first marker attached to the distal end ofthe robotic arm relative to a second marker attached to the base whilethe distal end of the robotic arm completes movements of theregistration or calibration routine, wherein the movements of theregistration or calibration routine comprise automated movements ormanual movements.
 13. The method of claim 8, wherein the registration orcalibration routine is configured to register the distal end of therobotic arm relative to a base tracking array attached to the base suchthat a position of the distal end of the robotic arm can be definedbased on a tracked position of the base tracking array collected by thetracking system and angles of joints of the robotic arm.
 14. The methodof claim 8, wherein determining the starting pose comprises calculatingthe starting pose based on a position of the movable base.
 15. One ormore non-transitory computer-readable media storing program instructionsthat, when executed by one or more processors, cause the one or moreprocessors to perform operations comprising: determining a starting posefor a registration or calibration routine for a robotic arm extendingfrom the base, the starting pose corresponding to an expected positionof a surgical field relative to the base; controlling the robotic arm toautomatically move the robotic arm to the starting pose; and in responseto successful automatic movement to the starting pose for theregistration or calibration routine, providing the registration orcalibration routine for the robotic arm.
 16. The non-transitorycomputer-readable media of claim 15, the operations further comprising:defining an approach area; in response to the robotic arm entering theapproach area, providing an option for a user to initiate the automaticmovement to the starting pose for the registration or calibrationroutine.
 17. The non-transitory computer-readable media of claim 16, theoperations further comprising: causing a display screen to display afirst graphic instructing a user to move the robotic arm into theapproach area; and in response to the robotic arm entering the approacharea, causing the display screen to display a second graphic instructingthe user to engage an input device to initiate the automatic movement.18. The non-transitory computer-readable media of claim 15, whereincontrolling the robotic arm to automatically move to the starting posefor the registration or calibration routine comprises: receiving asignal indicative of whether an input device of the robotic device isbeing engaged by a user; providing the automatic movement if an inputdevice of the robotic device is being engaged by the user; and stoppingthe automatic movement if the input device is not being engaged by theuser.
 19. The non-transitory computer-readable media of claim 15,wherein providing the registration or calibration routine comprisesobtaining tracked positions of a first marker attached to the distal endof the robotic arm relative to a second marker attached to the basewhile the distal end of the robotic arm completes movements of theregistration or calibration routine.
 20. The non-transitorycomputer-readable media of claim 15, wherein determining the startingpose comprises calculating the starting pose based on the position ofthe base.